Transurethral microwave thermotherapy for management of benign prostatic hyperplasia: durability of response

Abstract

Objectives. The durability of clinical efficacy of transurethral microwave thermotherapy (TUMT) by Prostatron using a low-energy protocol (maximum power, 50 W) was evaluated on an outpatient basis in patients with symptomatic benign prostatic hyperplasia (BPH).Methods. One hundred eighteen patients were followed up for longer than 3 months (13.4 ± 9.5 months; mean ± SD). All evaluations were made at baseline and then 3, 6, 12, 24, and 36 months after therapy.Results. International Prostate Symptom Score (IPSS) significantly decreased from 18.2 to 10.6 at 6 months (P <0.01), representing a mean improvement of 41% under the baseline. Peak flow rate increased from the baseline of 8.3 mL/s to 10.3 mL/s at 6 months (P <0.01). The improvement in terms of mean values of both parameters was sustained up to 24 months. Six of 44 patients (14%) who were followed up for 31 months on average required transurethral resection of the prostate for recurring obstructive symptoms and 10 additional patients (23%) had to be treated with various drug regimens. When the clinical outcome was evaluated in terms of improvement from the baseline according to a response criteria, disease-free rates for IPSS (more than 25% improvement from the baseline) were 76% at 12 months, 77% at 24 months, and 61% at 36 months. Disease-free rate for peak flow rate (more than 2.5 mL/s from the baseline) was sustained in 44% by 12 months and in 48% by 24 months. The overall outcome of the treatment was assessed by adding scores based on both subjective and objective efficacy criteria. At 6 months, 67% of the patients were responders, and 15 of 21 (71%) remained as responders at 24 months. Patients who had estimated prostate volume smaller than 30 cc showed more marked improvement in peak flow rate (P <0.02), and those with baseline IPSS of 20 or more showed greater reduction of IPSS (P <0.05) at 24 months compared with each counterpart.Conclusions. After TUMT with a low-energy protocol, satisfactory results were obtained and the improvement seems to last at least for 24 months. This low-energy protocol may be most beneficial in patients with relatively small size of the prostate.